Offshore drilling rig



DCC. 5, A A ASHTON OFFSHORE DRILLING RIG Q.Filed July 3o, 1957 2 Sheets-Sheet 1 IMF INVENTOR ALBERT A. ASHTON.

Dec. 5, 1961 A. A. ASHTON 3,011,318

OFFSHORE DRILLING RIG Filed July 30, 1957 2 Sheets-Sheet 2 1NVENT0R,. 4l ,52g l /4/ ALBE/rr AASHTO/v.

' //formy States Patent Oiice Patentedy Dec. 5, 1961 3,011,318 FFSHORE DRILLING RIG Albert A. Ashton, Houston, Tex.,l assigner to The Youngstown Sheet and Tube Company, Youngstown, Ohio, a corporation of Ohio Filed `Iuly 30, 1957, Ser. No. 675,121, 19 Claims. Cl. 61-46.5)

This invention relates to equipment `for the offshore drilling of wells, and relates in particular to amethod and means for installing equipment upon a supporting structure which extends upwardly from -an oishore underwater bottom, and `to the removal of such equipment after the well drilling loperationsV have been completed. In the normal practice of the invention the barge is employed which floats the well drilling equipment out to the previously installed supporting structure. Herein kthe term barge is employed in its broad sense as meaning any floating structure or vessel equipped so that it will carry a well drilling derrick and other well drilling equipment out tothe supporting structure, and being provided with means whereby it may perform the cooperative functions hereinafter set Iforth. Y

It is an object or" the invention to provide a method and means whereby the well drilling derrick is supported on the barge in such a manner that portions of the base of the derrick are exposed for engagement with the upper por-tion of a supporting structure which has been previously built in the body of Water, wherein the barge is moved into a position to support the derriok over the supporting structure, the derrick then being quickly lowered onto .the supporting structure and the barge thenl moved out from under the derrick, leaving the derrickstanding on the supporting structure, the b-arge then being moored alongside the derrick so as to serve as a tender during the conduct of drilling operations.

It is an object of the invention to provide the barge with ballast tanks and means for very rapidly flowing water into and out of theseballast tanks sothat a rapid lowering and raising of the barge is effected, making it possible to bring the dern'ck quickly into position on the supporting structure or -to quickly remove the derrick from the supporting structure after completion of the drilling operations. l 1

It is an object of the invention to provide a barge having an open notch in. an end thereof, with means vfor supporting the base of the derrick straddling this notch so that when the barge is moved into -a position wherein the upper end of the supporting structure lies within the notch,

' lowering of the barge will bring the derriok base into engagement with the upper end of the supporting structure, and it is a further object of the invention lto provide air pressure dilferential means for effecting a rapid movement of water into and out of the ballast tanks so that the derrick may be quickly brought into a position upon the supporting structure or quickly removed from the supporting structure, thereby facilitating the operations of installing and removing the derrick.

Further objects and advantages of the invention may be brought out in the followingl part of the specification wherein some details of construction have been described for the purpose of fully explaining the manner in which the invention may be practiced, without, however, intending to limit the scope of the invention which kis detined in the appended claims.

Referring to the accompanying drawings which are for illustrative purposes only: s

FIG. l is a schematic fragmentary elevational View showing a barge, with'well drilling equipment thereon, approaching a supporting structure which extends upwardly `from the underwater bottom;

' FIG. 2 is a fragmentary elevational view showing the barge supporting the derrick base' over the upr end of the supporting structure; l

FIG. 3 is a vpartly sectioned schematic elevational view showing a further step in the installation of the derrick upon the supporting structure;

FIG. 4 is a fragmentary schematic elevational view showing the bargel retracted from the position in which it has been shown in FIG. 3, to serve as -a tender `for well drilling operations;

LFIG. 5 is an enlarged fragmentary end view looking toward the rightward end of IFIG. 4;

FIG. 6 is an enlarged fragmentary sectional view taken as indicated bythe line 6-6 of FIG. 5;

FIG. 7 is a fragmentary 'partly sectioned plan view showing an alternative form of elevating and lowering equipment employing correlated hydraulic cylinders; and

FIG. 8 is a schematic sectional View taken as indicated by the line 8 8 of FIG. 7.

The barge 10, 'shown in =FIG. 1, has at the front end 11 thereof a notch 12 defined by side walls 13 and a back wall 14 as shown in FIG. 5. A derrick D, as shown in FIGS. 1 to 4,y is supported onv the barge 10, this derrick D including a ibase B which straddles the notch 12 and a mast M which rests in reclining position over a portion of 4the barge 10 and is not raised into erect position such as shown in FIG. 5 until the base B has been installed upon a supporting structure S which extends upwardly from the underwater bottom 15. The base B has a lioor 16 and fabricated side walls 17 extending downwardly from the opposite sides thereof as shown in FIGS. 1 and 5. As shown in FIG. 1, the side walls 17 have at the lowei ends thereof beams 13 which rest upon the deck 19 of the barge 10 above the side walls 13 of the notch 12. v

The mast M is connected to the base B by hinge means 2o around which the mast may be swung from reclining to vertical position. The reclining mast is supported by a transverse roller 21 supported by a structure 22 which extends upwardly `from the deck of the barge 101. -For engagement with the roller 21, the mast M has rails 23 adapted to roll upon the roller 21 when the barge is moved between the positions thereof shown in FIGS. 1 and 4. The derrick base B is provided with a gin pole 24 which is employed in raising and lowering the mast M and also the customary drawworks and power plant 25. K l

The barge 10 is provided with ballast tanks 26, only one of which is shown. y For inflow and outow of water from the water body W on which the barge 10 oats,

the ballast tanks are provided with duct means 27 of large size to `accommodate a rapid water flow, and valves 28 are provided for opening and closing the ducts 27. A power operated pump 30 is connected to the upper portions ofthe -ballast tank 26 by piping 31. This pump 30 may be operated as a pressure pump or a suction pump to either pump air pressure into the ballast tanks 26 or create a partial vacuum therein.

The supporting structure S is shown as four piles 32 which are driven into theY bottom 15 in a position surthe upper ends of the piles 32being then under the base oor 16; Prior to this time, with the valves 28 closed,

v the pump 30 is operated so as to produce a partial vacuum in the baliast tanks 26 above the water 34 therein so that at the time the barge is brought into the position in which it is shown in FIG. 2 there will be a large pressure differential in pressure between the external water W and the interiors of the ballast tanks 26. The next operation consists of detaching the base B from the barge and then quickly opening the valves 28 so that water may rush into the ballast tanks 26, causing the barge l to rapidly settie and thereby quickly lower the base B into engagement with the upper end of the supporting structure S. This rapid lowering of the base B, effected by the rapid settling of the barge 10, makes it possible to transfer thebase B to the upper end of the supporting structure without the bumping and pounding action of the base B against the supporting structure due to rocking or wave motion of the barge if the barge were allowed to settle slowly in the water.

By the method and means described in the foregoing, the barge lll may be lowered to a position wherein its deck will be spaced amply downwardly from the beams 1S of the derrick base B, as shown in FIG. 3. FIG. 6 shows bolt means 35 for seeming door beams 36 of the base 16 to the top plates 33 of the supporting structure S. After the base Bhas been secured to the supporting structure S the barge ld is backed off from the supporting structure and some of the water may be pumped out of the ballast tanks so as to raise the barge into the operating position in which it is shown in FiGS. 4 and 5. The barge lt? is provided with a cover plate 37 adapted to be rolled from the retracted position in which it is shown in FlG. 'l into a position, as shown in FIG. 4, wherein it covers the notch 12 of the barge which now, due to the backing off of the barge, occupies a position retracted from the base B. The mast M may be raised into Vertical position at any time after the base B has been firmly secured to the upper end of the supporting structure S.

When removal of the drilling equipment from the upper end of the supporting structure S is desired, the procedure described in the foregoing is reversed. Water will be fed into the ballast tanks to lower the barge 1i) so that its forward end ilv can be moved under the base B of the derrick, as shown in FIG. 3, and the mast g M lowered into reclining position. Then the pump means 39 is employed to build up `an air pressure in the ballast tanks 26. After removing the securing means so thatvthe base B can be lifted from the upper end of the supporting structure S, the valve 28 is quickly opened so that air pressure in the ballast tanks 26 will rapidly discharge water therefrom so that the barge ltl will quickly rise into the position in which it is shown in FIG. l2, engaging the beams 18 ofthe base B and lifting the 'base B ofi from the upper ends of the piles 32. Then the barge l may be moved away from the supporting structure as shown in FIG. l.

In FIGS. `7 and 8, I schematically show an alternative means for rapidly raising and lowering the derrick relative to the supporting structure S. Hydraulic jacks Wandel are mounted in the barge l0 in pairs on opposite sides of the notch i2 so that the upper ends 43 of the jacks will be positioned to receive the beams 18 of the derrick base B. The jacks al? and 4l each consists of a stationary piston 44 with a cylinder 4S movable upwardly thereon. The jacks are connected to a hydraulic system 46 including pump means 47 and an accumulator 48 for effecting raising and lowering of the jack cylinders 45. This rorm of the invention also includes means for correlating the vertical movements of the jack cylinders 45'. In the form of the invention disclosed this correlating means comprises rack and gear interconnections between the cylinders 45 so that they must all move upwardly and downwardly in unison. For example, the jacks and the jacks 4l are interconnected by pinions 56* fixed on the ends of the shaft 51, these pinions 50 engaging racks 52 secured to the cylinders 4S. Also, the shafts 5l are connected so that they will rotate in unison by bevel gear sets 55 which connect the ends of the shafts 51 with a transverse shaft 56.

I claim:

1. In equipment for the installation of a derrick on a previously erected supporting structure which extends upwardly from the underwater bottom, said derrick to provide generally above-water support means for the underwater drilling of a well: a derrick comprising a base, a .mast hinged to the base so as to be swung between upkright and reclining positions, means to swing the mast be- 'tween said positions and means on the base to perform drilling operations; a supporting structure extending upwardly from the underwater bottom; a barge movable on the water to a position to cooperate with said supporting structure, said barge having a notch therein adapted to receive the upper portion of said supporting structure, means on said barge supporting said derrick positioned with its base extending across said notch, said barge having ballast tank means equipped with water duct means through which water may flow into and out of said ballast tank means, pressure pump means to create `a gas pressure in said ballast tankmeans, vacuum pump means operative to create a partial vacuum in the upper portion of said ballast tank means, and valve means for said water duct means to open the same so that water may flow out of or into said ballast tank means under the pressure dierential of either air pressure or partial vacuum in said ballast tank means, to relatively rapidly lower and raise said derrick relative to the upper end oi said supporting structure; means detachably connecting said base to said barge; means toconnect said base to said supporting structure; roller means on said barge support ing the projecting portion of said mast and enabling relative movement of said mast in reclining position on said barge as the barge is backed off from said supporting structure to bring the notch. away from its position receiving the upper portion of said supporting structure; and a cover member movable on said barge into a position covering said notch while said barge is positioned adjacent said supporting structure so as to kcooperate with said derrick in the performance of well drilling operations.

2. In equipment for the installation of a derrick on a previously erected supporting structure which extends upwardly from the underwater bottom, said derrick to provide generally above-water support means for the underwater drilling of a well: a derrick comprising a base, a mast hinged tothe base so as to be swung between upright and reclining positions, means to swing the mast between said positions and means on the base to perform drilling operations; a barge movable on the water to a position to cooperate with a previously erected supporting struc ture, said barge having a notch therein adapted to receive the upper portion of said supporting structure, means on said barge supporting said derrick positioned with its base extending across said notch, said barge having ballast tankl means equipped with water duct means through which water may iiow into and out of said ballast tank means, pressure pump means to create a gas pressure in said ballast tank means, vacuum pump means operative to create a partial vacuum in the upper portion of said ballast tank means, and valve means for said water duct means to Vopen the same so that water may ow out of or into said ballast tank means under the pressure diiferential of either air pressure or partial vacuum in said ballast tank means, to relatively rapidly lower and raise said derrick relative to the upper end of said supporting structure; means connecting said base to said barge; and means to connect said base 4to said supporting structure.

3. In equipment for the installation of a derrick on a previously erectedsupporting structure which extends upwardly from the underwater bottom, said derrick to provide generally above-water support means for the underwater drilling of a well: a derrick comprising a base, a mast hinged to the base so as to be swung between upright and reclining positions, means to swing the mast between said barge having a notch therein adapted to receive the upper portion of said supporting structure, means on said barge supporting said derrick positioned with its base extending across said notch, said barge having ballast tank means equipped with Water duct means through which water may flow into and out of said ballast tank means, pressure pump means to create a gas pressure in said ballast tank means, vacuum pump means operative to create a partial vacuum in the upper portion of said ballast tank means, and valve means for said water duct means to open the same so that water may iiow out of or into said ballast tank means under the pressure difierential of either air pressure or partial Vacuum in said ballast tank means, to relatively rapidly lower and raise said derrick relative to the upper end of said supporting structure; roller means on said barge supporting the projecting portion of said mast and enabling `relative movement of said mast in reclining position on said barge asv the barge is backed off from said supporting structure to bring the notch away from its position receiving the upper por-tion of said supporting structure; and a cover member movable on said barge in a position covering said notch while said barge is positioned adjacent said supporting srtucture so as to cooperate with said derrick in the performance of well drilling operations.

4. 'In equipment for the installation of a derrick on a previously erected supporting structure which extends upwardly from the underwater bottom, said derrick to provide generally above-water support means for the underwater drilling of a well: a derrickrcomprising a base, a mast hinged to the base so as to be swung between upright and reclining positions, means -to swing the mast between said positions and means on the base to perform drilling operations, said base having barge engaging members formed on its lower surface along two opposite longitudinal sides thereof and supporting structure engaging means upwardly between said barge engaging members; and a barge movable on the water to a position to cooperate with a previously erectedk supporting structure, said barge having a notch thereinadapted to receive the upper portion of said supporting structure, means engaging said barge engaging members of said base disposed along opposite sides of said notch supporting said derrick position with its base extending across said notch, said barge having ballast tank means equipped'with water duct meansr through rwhich water may flow into and out of said ballast tank means, pressure pump means to create a gas pressure in said ballast tank means, vacuum pump means operative to create a vpartial vacuum in the upper portion of said ballast tank means, and valve means for said water duct means to open the same so that water may ow out of or into said ballast tank means under the pressure differentialy of either air pressure or partial vacuum in said ballast tank means, to relatively rapidly lower and raise said derrick relative to the upper end of said supporting structure.

5.- In equipment for the installation of a derrick on a previously erected supporting structure which extends upwardly from the underwater bottom, said derrick to provide generally above-water support means for the underwater drilling of a well: a derrick comprising a base, a mast hinged to the base so as to be swung between upright and reclining positions, means to swing the mast between said positions and means on the base vto perform drilling operations; a barge movable on the water to a. position to cooperate with a previously erected supporting structure, said barge having a notch therein adapted lto vreceive the upper portion of said supporting structure, means on said barge supporting said derrick positioned with its base extending across said notch,'sai`cl barge-having means to raise and lower said derrick so as to lower it onto and lift it off from said supporting struct-ure comprising hydraulic jack members disposed between said barge and the base of said derrick, means to charge and Vdischarge said hydraulic jack members with i'luid, and means to'correlate the upward and downward movements of said jack members; means detachably connecting said base to said barge; means vto connect said base to said supporting structure; roller means on said barge supporting the projecting portion of said mast and enabling relative movement of said i mast in reclining position and said barge as' the barge is backed ofi from said supporting structure to bring the notch away from its position receiving the upper portion of said supporting structure; and a cover member movable on said barge into a position covering said notch while said barge is positioned adjacent said supportingk structure so as to cooperate with said-derrick in the performance of well drilling operations.l

ymast hinged to the base so as to be swung between upright and reclining positions, means to swing the mast between said positions and means on the base to perform drilling operations; and a barge movable on the water to a position to cooperate with a previously erected supporting structure, said barge having a notch therein adapted to receive the upper portion of said supporting structure, means on saidbarge supporting said derrick positioned with its base extending across said notch, said barge having means to raise and lower said derrick so as to lower it onto and lift it oit from said supporting structure comprising hydraulic jack members disposed between said barge and the base of said derrick, means to charge and discharge said hydraulic jack members With fluid7 and means to correlate the upward and downward movements of said jack members'.

7. In equipment for the installation of a derrick on a previously erected supporting structure which extends upwardly from the underwater bottom, said derrick to pro-` vide generally above-water support means for the underwa/ter drilling of a well: a derrick comprising a base, a mast hinged to the base so as lto be swung between upright and reclining positions, means to swing the mast between said positions and means on the base to perform drilling operations; a barge movable on the water to a position to cooperate with a previously erected supporting structure,

said barge having means to raise and lower said derrick l so as to lower it onto and lift it oi from said supporting structure comprising hydraulic jack members disposed between said barge and the base of said derrick, means to charge and discharge said hydraulic jack members with uid, and means to correlate the upward and downward movements of said jack members; means detachably connectingsaid base to said barge; and means on said base to connect said base to said supporting structure.

8. In equipment for the installation of a derrick on a previously erected supporting structure which extends upwardly from the underwater bottom, said derrick to provide generally above-water support means for the underwater drilling of a well: a derrick comprising a base, a mast hinged to the base so as to be swung between upright and reclining positions, means to swing the mast between said positions and means on the base to perform drilling operationsyand a barge movable on the water to a position to cooperate with a previously erected supporting structure, said barge having means to raise and lower said derrick so as to lower it onto and lift it olf from said supporting structure comprising hydraulic jack members disposed between said barge and the base of saidderrick.

9. iIn equipment for the installation of a derrick ona previously erected supporting structure which extends upwardly from the underwater bottom, said derrick to provide generally above-water support means for the underwater drilling of a well: a derrick comprising a base, a

mast hinged tothe base so as to be swung between upright and reclining positions, means to swing the mast between said positions and means on the base to perform drilling operations; a barge movable on the water to a position to cooperate with apreviously erected supporting structure, said barge having means supporting the derrick so that it may be brought into a position over said supporting structure; means in said barge to effect arapid lowering of the derrick onto said supporting structure, said means supporting the derrick comprising ballast tank means connected to the barge, a duct connected to said ballast tank means to permit inllow of water into and outow of water from said ballast tank means, valve means to close said duct; and pump means operable to create a vacuum in said ballast -tank means so that when said valve is opened water will rapidly enter said ballast tank means and effect a rapid lowering of said barge so that said derrick will be rapidly lowered onto said supporting structure.

l0. In equipment for the installation of a derrick on a previously erected supporting structure which extends upwardly from the underwater bottom, said derrick to provide generally above-water support means for the undertank means under force of said air pressure to rapidly raise said barge structure into engagement with said der- V rick; and lifting the derrick from said supporting strucwater drilling of a well: a derrick comprising a base,

mast hinged to the base so as to be swung between upright and reclining positions, means to swing the mast between said positions and means on the base to perform driiling operations; a barge movable on the water to a position to cooperate with a previously erected supporting structure, said barge having means supporting the derrick so that it may be brought into a position over said supporting structure; means in said barge to effect a rapid lowering of the derrick onto said supporting structure, said means supporting the derrick comprising ballast tank means connected to the barge, a duct connected to said ballast tank means to permit inflow of water into and outflow of water from said ballast tank means, valve means to close said duct; pump means operable to create a vacuum in said ballast tank means so that when said valve is opened water will rapidly enter said ballast tank means and effect a l rapid lowering of said barge so that said derrick will be rapidly lowered onto said supporting structure; and pump means operable when it is desired to raise the derrick from engagement with said supporting structure to apply a gas pressure to the interior of said ballast tank means above the water therein, rapidly discharge the water from said ballast tank means and raise the barge upon the subsequent opening of said valve means.

ll. In a method of employing a barge equipped with ballast tank means to install a derrick on the top of a previously erected supporting structure which extends up from the bottom underlying a body of water: supporting the derrick on the barge so that a downwardly faced portion thereof is exposed for engagement with the top of the supporting structure; discharging water from the ballast tank means to raise the barge in the water and to raise said downwardly faced portion of the derrick above said supporting structure; moving the barge to bring the derrick into a position over the supporting structure; withdrawing air from said ballast tank means to create a partial vacuum therein; then rapidly admitting water into'said ballast tank means under action of said partial vacuum therein to quickly lower said derrick onto said supporting structure; detaching said derrick from said barge; and moving said barge away from under said derrick.`

`\l2. The method of employing a barge structure equipped with ballast tank means to remove a derrick from the top of a supporting structure which extends up from the bottom underlying a body of water, comprising: admitting water into the ballast tank means to lower said barge structure in the water; moving the barge structure to bring a portion thereof into a position under the derrick; pumping gas into said ballast tank means to create a gas pressure in the upper portion of said ballast tank means; then effecting discharge of water from said ballast ture.

.13. In a method of employing a barge equipped with ballast tank means to install a derrick on the top of a previously erected supporting structure which extends up from the bottom underlying a body of water: supporting the derrick on two spaced members on the barge so that a downwardly faced portion thereof is exposed for engagement with the top of the supporting structure; discharging water from the ballast tank means to raise the barge in the water and to raise said downwardly faced portion of the derrick above said supporting structure; moving the barge to bring the derrick into a position over the supporting structure and to bring each of said spaced members on an opposite side of said supporting structure; flowing water into said ballast tank means to lower the barge and thereby lower said derrick onto said supporting structure; detaching said derrick from said barge; and moving said barge away from under said derrick.

14. In a method of employing a barge equipped with ballast tank means to install a derrick on top of a supporting structure which extends up yfrom the bottom underlying a body of water: supporting the derrick on the barge so that a downwardly faced portion thereof is exposed for engagement with the top of the supporting structure; moving the barge to bring the derrick into position over the -supporting structure; then rapidly admitting water into said ballast -tank means so as to quickly lower said derrick onto said supporting structure; detaching said derrick from said barge; and moving said barge away from under said derrick.

15. In combination, a barge and -derrick for installing the derrick on a previously erected support structure which extends upwardly from the underwater bottom, said derrick to provide a generally above-water support means for the underwater drilling of a well, comprising: a barge movable on the water, said barge having a notch therein at one end4 adaptable to receive a previously erected derrick supporting structure therein; a derrick having a base; a mast hinged to said base so as to be swingable between upright and reclining positions; means on said base to swing said mast between said positions and means on the base to perform drilling operations, said base lhaving barge engaging members formed on its lower surface along two opposite longitudinal sides thereof, and supporting structure engaging meansupwardly between said barge engaging members; and means on said barge disposed along opposite sides of said notch detachably engaging said barge engaging members of said base and detachably supporting said derrick in position with said base extending across said notch, said barge having ba-llast tank means equipped with water duct means through which water may flow into and out of the said ballast tank means, pressure pump means to create a gas pressure in said ballast tank means, Vacuum pump means operative to create a partial vacuum in the upper portion of said ballast tank means, and valve means for said water duct means to open the same so that water may flow out of or into said ballast tank means under the pressure differential of either air pressure or partial vacuum in said ballast tank means, to rapidly lower and raise said derrick relative to the upper endof said supporting structure.

f16. In combination, a barge and derrick for installing the derrick on a previously erected support structure which extends upwardly from the underwater bottom, said derrick to provide a generally above-water support means for the underwater drilling of a well, comprising: a barge movable on the water, said barge having a notch therein atone end adaptable to receive a previously erected derrick supporting structure therein; a derrick having a base; a mast hinged to said base so as to be swingable between upright and reclining positions; means on said base to swing said mast between said positions and means on the base to perform drilling operations, said base having barge engaging members formed on its lower surface along two opposite longitudinal sides thereg said baseextending across said notch, said barge having ballast, tankmeans equipped with water duct means through whichwater may flow into and out of the said ballast tank means, pump means for ballasting and deballasting said ballast tank means, and valve means for said water duct means to open the same so that water may ow out of or into said ballast tank means according to whether the pump is operating to ballast or de-ballast, to lower and raise said derrick relative to the upper end of said supporting structure. l

17. In combination, a barge and derrick for installing the derrick on a previously erected support structure which extends upwardly from the underwater bottom, said derrick to provide a generally above-water support means for the underwater drilling of a well, comprising: a barge movable on the water, said barge having a notch therein at one end adaptable to receive a previously erected derrick supporting structure therein; a' derrick formed on its lower surface along two opposite longitudinal sides thereof and having supporting structure engaging means upwardly between said barge engaging members, said barge having supporting members supporting the derrick so that it may be brought into a position over said previously erected supporting structure, said supporting members being spaced laterally lying under and in engagement with said barge engaging members of said base, said supporting members defining a notch at the end ofthe barge to receive said previously erected supporting structure therein; and means in said barge to effect a rapid lowering of the derrick onto said previouslyY erected supporting structure.

19. In combination, a barge and derrick for installing the derrick on a previously erected support structure which extends upwardly from the underwater bottom, said derrick to provide a generally above-water support means for the underwater drilling of a well, comprising: a barge movable on the water, said barge having a notch therein at one end adaptable to receive a previously erected derrick supporting structure therein; a derrick having a base; a mast hinged to said base so as to be Y swingable between upright Vand reclining positions; means having a base; a mast hinged to said basev so as to be of, and supporting structure engaging means upwardlybetween said barge engaging members; and means on said barge disposed along opposite sides of said notch v detachably engaging saidbarge engaging members of said base and detachably supporting said derrick in position with said base extending across said notch, said bargev having means `to raise and lower said derrick so as to lower it onto and lift it off of a previously erected derricksupporting structure, said last mentioned means comprising hydraulic jack members disposed between said barge and the base of said derrick, and means to correlate the upward and downward movements of said jack members.

118. In equipment for installation of a `derrick on a previously erected supporting structure which extends upwardly from the underwater bottom, said derrick to provide generally above-water support means for the underwater drilling of a well: a derrick comprising a base, a mast hinged to the'base so as to be swingable between upright and reclining positions, means to swing the mast between said positions and means on the base to perform drilling operations; a barge movable on the waterv to a position to cooperate with a previously erected supporting structure, said base having barge engaging members lon said base to swing said mastl betweenA saidpositions and means on the base to perform drilling operations, said base having barge engaging members formed on its lower surface along two opposite longitudinal sides thereof, and supporting structure engaging means upwardly between said barge engaging members; means on said barge disposed along opposite sides of said notch detachably engaging said barge engaging members of said base and detachably supporting said derrick in position with said base extending across said notch; kand means within said barge to raise and lower said derrick with respect i ol of said last mentioned structure.

References Cited in the iile of this patent ,UNITED STATES PATENTS 36,606 Du Bois Oct. 7, 1862 1,850,507 Larsson Mar, 22, 1932 2,475,933 Woolslayer July 12, 1949 2,699,042 Hayward Jan. 11, 1955 2,715,954 Rowan Aug. 23, 1955 2,817,212 Stubbs Dec. 24, 1957 2,829,741 Selberg Apr. 8, 1958 2,959,015 Beck Nov. 8, 1960 FOREIGN PATENTS 763,864 Great Britain Dec. 19, 1956 OTHER REFERENCES The Oil and Gas Journal, May 10, 1947, pages 6-63 and 83.

Engineering News Record, Dec. 27, 1945, pages 53-54. 

